Re: TA/FA - the best I've seen use both. Some use the TA to identify the opportunities then complete FA to validate, some vice versa. It's whatever works for the individual.
Just purely on anecdotal observation I would guess guys like Orwell/Jako would fit into category a) and Pisces/Hera into category b).
I tend to agree that it would be extremely difficult to do one exclusively and make a good living.
I'm also in category b). My charting skills are abysmal, but I know enough to help me with good entry and exists, and also enough to identify when we are at critical junctures. I often pick up bit's a pieces that help me along the way and it's a constant learning game, not matter how experienced the punter.